mm: rejig pageblock mask definitions

- Add a PAGEBLOCK_ prefix to the names to avoid polluting the "global
  namespace" too much.

- This new prefix makes MIGRATETYPE_AND_ISO_MASK look pretty long. Well,
  that global mask only exists for quite a specific purpose, and is
  quite a weird thing to have a name for anyway. So drop it and take
  advantage of the newly-defined PAGEBLOCK_ISO_MASK.

Link: https://lore.kernel.org/20260513-page_alloc-unmapped-prep-v1-3-dacdf5402be8@google.com
Signed-off-by: Brendan Jackman <jackmanb@google.com>
Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Wei Xu <weixugc@google.com>
Cc: Yuanchu Xie <yuanchu@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

2 files changed, 12 insertions, 12 deletions

diff --git a/include/linux/pageblock-flags.h b/include/linux/pageblock-flags.h
index e046278a01fa..9a6c3ea17684 100644
--- a/include/linux/pageblock-flags.h
+++ b/include/linux/pageblock-flags.h
@@ -36,12 +36,12 @@ enum pageblock_bits {
 
 #define NR_PAGEBLOCK_BITS (roundup_pow_of_two(__NR_PAGEBLOCK_BITS))
 
-#define MIGRATETYPE_MASK (BIT(PB_migrate_0)|BIT(PB_migrate_1)|BIT(PB_migrate_2))
+#define PAGEBLOCK_MIGRATETYPE_MASK (BIT(PB_migrate_0)|BIT(PB_migrate_1)|BIT(PB_migrate_2))
 
 #ifdef CONFIG_MEMORY_ISOLATION
-#define MIGRATETYPE_AND_ISO_MASK (MIGRATETYPE_MASK | BIT(PB_migrate_isolate))
+#define PAGEBLOCK_ISO_MASK	BIT(PB_migrate_isolate)
 #else
-#define MIGRATETYPE_AND_ISO_MASK MIGRATETYPE_MASK
+#define PAGEBLOCK_ISO_MASK	0
 #endif
 
 #if defined(CONFIG_HUGETLB_PAGE)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3e4c4af06f37..0278d642445a 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -364,7 +364,7 @@ get_pfnblock_bitmap_bitidx(const struct page *page, unsigned long pfn,
 #else
 	BUILD_BUG_ON(NR_PAGEBLOCK_BITS != 4);
 #endif
-	BUILD_BUG_ON(__MIGRATE_TYPE_END > MIGRATETYPE_MASK);
+	BUILD_BUG_ON(__MIGRATE_TYPE_END > PAGEBLOCK_MIGRATETYPE_MASK);
 	VM_BUG_ON_PAGE(!zone_spans_pfn(page_zone(page), pfn), page);
 
 	bitmap = get_pageblock_bitmap(page, pfn);
@@ -437,7 +437,7 @@ bool get_pfnblock_bit(const struct page *page, unsigned long pfn,
 __always_inline enum migratetype
 get_pfnblock_migratetype(const struct page *page, unsigned long pfn)
 {
-	unsigned long mask = MIGRATETYPE_AND_ISO_MASK;
+	unsigned long mask = PAGEBLOCK_MIGRATETYPE_MASK | PAGEBLOCK_ISO_MASK;
 	unsigned long flags;
 
 	flags = __get_pfnblock_flags_mask(page, pfn, mask);
@@ -446,7 +446,7 @@ get_pfnblock_migratetype(const struct page *page, unsigned long pfn)
 	if (flags & BIT(PB_migrate_isolate))
 		return MIGRATE_ISOLATE;
 #endif
-	return flags & MIGRATETYPE_MASK;
+	return flags & PAGEBLOCK_MIGRATETYPE_MASK;
 }
 
 /**
@@ -534,11 +534,11 @@ static void set_pageblock_migratetype(struct page *page,
 	}
 	VM_WARN_ONCE(get_pageblock_isolate(page),
 		     "Use clear_pageblock_isolate() to unisolate pageblock");
-	/* MIGRATETYPE_AND_ISO_MASK clears PB_migrate_isolate if it is set */
+	/* PAGEBLOCK_ISO_MASK clears PB_migrate_isolate if it is set */
 #endif
 	__set_pfnblock_flags_mask(page, page_to_pfn(page),
 				  (unsigned long)migratetype,
-				  MIGRATETYPE_AND_ISO_MASK);
+				  PAGEBLOCK_MIGRATETYPE_MASK | PAGEBLOCK_ISO_MASK);
 }
 
 void __meminit init_pageblock_migratetype(struct page *page,
@@ -564,7 +564,7 @@ void __meminit init_pageblock_migratetype(struct page *page,
 		flags |= BIT(PB_migrate_isolate);
 #endif
 	__set_pfnblock_flags_mask(page, page_to_pfn(page), flags,
-				  MIGRATETYPE_AND_ISO_MASK);
+				  PAGEBLOCK_MIGRATETYPE_MASK | PAGEBLOCK_ISO_MASK);
 }
 
 #ifdef CONFIG_DEBUG_VM
@@ -2140,15 +2140,15 @@ static bool __move_freepages_block_isolate(struct zone *zone,
 	}
 
 move:
-	/* Use MIGRATETYPE_MASK to get non-isolate migratetype */
+	/* Use PAGEBLOCK_MIGRATETYPE_MASK to get non-isolate migratetype */
 	if (isolate) {
 		from_mt = __get_pfnblock_flags_mask(page, page_to_pfn(page),
-						    MIGRATETYPE_MASK);
+						    PAGEBLOCK_MIGRATETYPE_MASK);
 		to_mt = MIGRATE_ISOLATE;
 	} else {
 		from_mt = MIGRATE_ISOLATE;
 		to_mt = __get_pfnblock_flags_mask(page, page_to_pfn(page),
-						  MIGRATETYPE_MASK);
+						  PAGEBLOCK_MIGRATETYPE_MASK);
 	}
 
 	__move_freepages_block(zone, start_pfn, from_mt, to_mt);